Here is the link:
We want to buy OEM type of license what means, that everybody who is using Yii will be able to use this redactor for free (it terms of official extension). If you want to help with this start-up, plz contribute your "1 dollar" to accomplish our goal
Here is the original topic:
Sam Dark is responsible for gathering money, so you can write him PM in this forum also.
Also there was a good proposal (by lancecoder) - to create a special fund for investing of buying licenses for such good stuff I think it will be useful for every user of Yii